1
dc1007cf
DEMO MANUAL DC1007C
DESCRIPTION
LTC4088
High Efficiency Battery
Charger/Power Manager
Demonstration Circuit 1007 is a high efficiency USB power
manager with PowerPath™ control and Li-Ion/Polymer
battery charger featuring the LT C
®
4088. It includes a syn-
chronous switching input regulator, a full featured battery
charger and an ideal diode. Designed specifically for USB
applications, the LTC4088’s switching regulator automati-
cally limits its input current to either 100mA, 500mA or
1A for wall-powered applications via logic control. There
are also 2.5mA and 500µA suspend modes to prevent the
battery from running down when the product is connected
to a suspended USB bus.
The switching input stage provides power to VOUT where
power sharing between the application circuit and the
battery charger is managed. Unlike linear PowerPath
controllers, the LTC4088’s switching input stage can use
nearly all of the 0.5W or 2.5W available from the USB port
with minimal power dissipation. This feature allows the
LTC4088 to provide more power to the application and L, LT, LTC, LTM, Linear Technology, the Linear logo and PowerPath are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
PERFORMANCE SUMMARY
battery and eases thermal issues in space constrained
applications.
An ideal diode ensures that the system power is available
from the battery when the input current limit is reached or
if the USB or wall supply is removed. The optional external
P-channel MOSFET supplements the internal ideal diode
by reducing RON and increasing efficiency.
A CHRG LED indicates four possible states of the battery
charger. Charging is indicated when the LED is steady-ON.
Not charging is indicated by a steady-OFF. A NTC fault is
indicated by a slow blinking rate (1.5Hz) and a bad battery
is indicated by a fast blinking rate (6.1Hz).
The LTC4088 is available in the low profile 14-Lead
4mm × 3mm × 0.75mm DFN surface mount package.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1007C
Specifications are at TA = 25°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VBUS Input Voltage Range 4.35 5.5 V
VOUT Mode and Load Dependent 3.5 4.7 V
VLDO3V3 3.3V Load and VOUT Dependent 3.3 V
VBAT Output Float Voltage (Constant Voltage Mode) 4.2 V
IBAT Output Charge Current (Constant Current Mode) RPROG Equals 2kΩ 0.5 A
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dc1007cf
DEMO MANUAL DC1007C
QUICK START PROCEDURE
Demonstration circuit 1007 is best evaluated using a Li-
Ion/Polymer battery. When using a battery simulator for
evaluation, oscillations must be verified with a real battery
at the same conditions because it is difficult to match the
impedance of a real battery, which is required for battery
charger stability.
Refer to Figure 1 for the proper measurement and equip-
ment setup and follow the procedure below.
1. If using an external supply, connect a 0V to 6V, 1.5A
supply with voltage adjusted to 0V between the VBUS
and GND terminals. Connect a voltmeter across the
VBUS and GND terminals. If using the USB input op-
tion, have cable ready to plug in when all loads and
jumpers are set. Do not use the USB input and an
external supply at the same time.
2. Set JP1, NTC jumper to INT to use the demo board
resistor. To use an external NTC resistor, connect an
NTC resistor between J2 - J3 and the GND terminal.
Then set the NTC jumper to EXT.
3. Use Table 1 to set JP2, JP3, and JP4 (D0, D1, and D2
respectively) to select the desired input current limit
and charger status.
Table 1. Controlled Input Current Limit
D0 D1 D2 CHARGER ILIM
0 0 0 ON 100mA (1×)
0 0 1 OFF 100mA (1×)
0 1 0 ON 500mA (5×)
0 1 1 OFF 500mA (5×)
1 0 0 ON 1A (10×)
1 0 1 OFF 1A (10×)
1 1 0 OFF 500µA (SUSP)
1 1 1 OFF 2.5mA (SUSP)
4. Connect a 0mA to 25mA adjustable load in series
with an ammeter between the 3.3V and GND termi-
nals. Connect a voltmeter between the 3.3V and GND
terminals.
5. Connect a 0A to 2A adjustable load in series with an
ammeter between the VOUT terminal and the GND
terminal. Connect a voltmeter between the VOUT and
GND terminals.
6. Connect a partially charged (~3.6V) lithium-ion bat-
tery with the positive lead to the BAT terminal and the
negative lead to a GND terminal. Connect the positive
lead of a voltmeter to the BAT terminal and the nega-
tive lead to the GND terminal. Connect the positive
terminal of a voltmeter to PROG and the negative
terminal to GND to measure the current flowing into
the battery. The voltage on PROG will read 1V when
the maximum charge current is reached. The voltage
on CLPROG will read 1.188V when the input current
is reached. Observe VOUT and the 3.3V output.
IBAT =
V
PROG
RPROG
•103
1
IVBUS =IBUSQ +
V
CLPROG
R
CLPROG
• hCLPROG +1
( )
See the data sheet for the proper values of IBUSQ and
hCLPROG in the 1×, 5× and 10× modes.
7. If using the USB input, plug in the USB cable and ob-
serve the charge current, VOUT, and the 3.3V output.
If using an external power supply, slowly increase the
supply and observe that the LTC4088 starts to use
the VBUS input power as the VBUS reaches 4.35V.
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dc1007cf
DEMO MANUAL DC1007C
QUICK START PROCEDURE
8. Discharge the battery to 2.5V. If charger mode is on,
observe it is charging in trickle charge mode and
the charge current is 50mA. As the battery voltage
increases above 2.85V observe that the charger goes
into full constant current mode. Observe that VOUT
stays above 3.6V when the input current limit is not
exceeded. Remove the NTC jumper on JP2. Observe
the CHRG LED slow blinking rate. Also observe the
35KHz pulse with varying duty cycle between 4.7%
and 95.3% on the CHRG terminal with an oscilloscope.
Reinstall the NTC jumper.
9. Increase the VOUT load and observe when the input
current starts to limit (VCLPROG = 1.188V). When input
current limit is reached, VOUT drops from 300mV
above the BAT voltage to 15mV below the BAT volt-
age and the additional load transitions to the battery
through the ideal diode. Due to the high efficiency of
the switching regulator, the charge and load current
may be significantly above the input current depending
on the voltage on the BAT pin.
10. Repeat step 9 with different current limit modes.
11. Set the VBUS input supply to 5V. Observe the battery
current as the battery voltage increases above 4.1V.
The charge current starts to decrease as the battery
voltage increases towards 4.2V.
See the latest LTC4088 data sheet for more information
on how this part performs.
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dc1007cf
DEMO MANUAL DC1007C
APPLICATION INFORMATION
This demo circuit is designed to demonstrate the full
capability of the LTC4088 high efficiency battery charger.
Not all components are required in all applications. The
critical circuit components are on the top of the board
near the IC and listed in the Required Circuit Components
section of the Parts List
The input capacitor network of C7 and R13 is used to
dampen source lead inductances that commonly occur in
laboratory setups with twisted leads and a bench power
supply. When using an USB cable or adaptor cable this
input damping network will likely not be required. Please
note that the in-circuit capacitance of the specified 10µF,
0805 ceramic ceramic capacitor for C2 and C7 is approxi-
mately 5µF each at a VBUS greater than 4.25V.
Capacitor C4 is only required when using the 10× mode.
The LTC4088 requires a minimum of 10µF on the OUT
pin in 10× mode for voltage loop stability. As an alterna-
tive to using two smaller X5R capacitors, one larger X5R
ceramic capacitor would be acceptable, provided that the
actual in-circuit capacitance with 4.2V applied is greater
than 10µF.
Capacitor C5 is included to simulate a low impedance bat-
tery. It is especially helpful when testing the demo circuit
with a battery simulator comprised of a standard power
supply with a 3.6Ω power resistor across it. The leads
connecting the power supply to the demo circuit should
be a twisted pair to minimize lead inductance; although,
even twisted pairs can introduce enough inductance into
the circuit to cause instability in the battery charger sec-
tion without the presence of C5. Capacitor C5 will also
provide proper operation of the circuit without a battery
present. Refer to the data sheet for more discussion of
operation without a battery. If desired, it is possible to use
a ceramic capacitor in series with a low valued resistor to
stabilize the battery charger when no battery is present.
Please refer to the data sheet for the suggested capacitor
and resistance range.
When not using the 3.3V LDO (LDO3V3) connect VOUT
to LDO3V3 by installing R12 and removing C1.
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dc1007cf
DEMO MANUAL DC1007C
Figure 1. Proper Measurement Equipment Setup for DC1007C
APPLICATION INFORMATION
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dc1007cf
DEMO MANUAL DC1007C
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C1 CAP, CHIP, X5R, 1.0µF, 6.3V, 0402 MURATA, GRM155R60J105ME19D
2 1 C2 CAP, CHIP, X5R, 10µF, 10V, 0805 MURATA, GRM21BR61A106KE19L
3 1 C3 CAP, CHIP, X5R, 22µF, 6.3V, 0805 MURATA, GRM21BR60J226ME39L
4 1 C6 CAP, CHIP, X7R, 0.1µF, 16V, 0402 MURATA, GRM155R71C104KA88D
5 1 L1 IND, 3.3µH, 0.08Ω, 2.2A COILCRAFT, LPS4018-332MRC
6 1 R5 RES, 0402 2.94k 1% 1/16W VISHAY, CRCW04022K94FKED
7 2 R6, R7 RES, 0402 2k 1% 1/16W VISHAY, CRCW04022K00FKED
8 1 R14 RES, 0402 8R 25Ω 1% 1/16W VISHAY, CRCW04028R25FNED
9 1 U1 IC, USB BAT CHARGER/POWER MANAGER, DFN-14 LTC4088EDE
Additional Demo Board Circuit Components
10 1 C4 CAP, CHIP, X5R, 22µF, 6.3V, 0805 MURATA, GRM155R60J105ME19D
11 1 C5 CAP, CHIP OS-CON, 100µF, 6.3V, B6 PANASONIC, 6SVPC100MY
12 1 C7 CAP, CHIP, X5R, 10µF, 10V, 0805 MURATA, GRM21BR61A106KE19L
13 1 D1 LED 565NM GRN DIFF 0603 SMD LUMEX OPTO/COMPONENTS INC,
SML-LX0603GW-TR
14 1 Q1 XSTR, MOSFET P-CHANNEL SILICONIX, Si2333DDS
15 2 R1, R2 RES, 0402, 100k, 1%, 1/16W VISHAY, CRCW0402100KFKED
16 4 R3, R4, R8, R9 RES, 0402 0R 0Ω 1/16W VISHAY CRCW04020000Z0ED
17 1 R10 RES, 0402 510Ω 1% 1/10W VISHAY CRCW0402 5100 1%
18 0 R11 (OPT) RES., OPTION, 0402 OPT
19 0 R12 (OPT) RES, 0402 0R 0Ω 1/16W VISHAY CRCW04020000Z0ED
20 1 R13 RES., 1Ω, 1%, 1/16W, 0402 VISHAY, CRCW04021R00FKED
Hardware: For Demo Board Only
21 1 J1 CONN, USB MINI-B TYCO 440247-1
22 6 E1, E2, E8, E9, E10, E11 TEST POINT, TURRET, 0.094", MTG. HOLE MILL-MAX, 2501-2-00-80-00-00-07-0
23 10 E3, E4, E5, E6, E7, E12, E13, E14,
E15, E16
TEST POINT, TURRET, 0.064", MTG. HOLE MILL-MAX, 2308-2-00-80-00-00-07-0
24 4 JP1, JP2, JP3, JP4 HEADER, 3 PINS 2mm COMM 2802S-03G2
25 4 STANDOFFS KEYSTONE, 8831
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dc1007cf
DEMO MANUAL DC1007C
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
SCHEMATIC DIAGRAM
4
4
3
3
2
2
1
1
4 4
3 3
2 2
1 1
1
INTEXT
0
D2
D1
4.35V - 5.5V
1
0
0
D0
1
NTC
CHRG
1
1
0
0
0
CURRENT
LIMIT
0
1A (10X)
500mA (5X)
500mA (5X)
1
500uA (SUSP)
0
100mA (1X)
1
2.5mA (SUSP)
ON
1
100mA (1X)
0
1
1
1
1
1
0
0
OFF
D0
INPUT CURRENT LIMIT SETTINGS
ON
OFF
1
0
D2
ON
0
0
OFF
0
D1
OFF
1
VBUS
3.5V - 4.7V
2A
OPT
1A (10X)
CHARGER
STATUS
3.3V
25mA
OFF
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
1
DEMO CIRCUIT 1007C
11
High Efficiency Battery Charger / USB Power Manager
N/A
LTC4088EDE
NC
MM
7 - 25 - 16
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
1
DEMO CIRCUIT 1007C
11
High Efficiency Battery Charger / USB Power Manager
N/A
LTC4088EDE
NC
MM
7 - 25 - 16
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
1
DEMO CIRCUIT 1007C
11
High Efficiency Battery Charger / USB Power Manager
N/A
LTC4088EDE
NC
MM
7 - 25 - 16
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
MM
PROTOTYPE
-1 7 - 25 - 16
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
MM
PROTOTYPE
-1 7 - 25 - 16
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
MM
PROTOTYPE
-1 7 - 25 - 16
USBMINI-B
J1
J1
VBUS 1
D- 2
D+ 3
ID 4
GND 5
E4
D0
R10
510
C2
10uF
10V
0805
E1
TP2 D+
E10 BAT
FLOAT=4.2V
0.5A
R9
0.00
R4
0.00
E11
GND
R14
1%
8.25
TP3 ID
E2
GND
R2
1%
100K
C4
22uF
6.3V
0805
R12
OPT
JP4
+
C5
100uF
6.3V
OS-CON
2 1
JP3
E14
C/X
R11
OPT
D1
GRN
E9
GND
R3
0.00
TP1 D-
C3
22uF
6.3V
0805
JP1
E7 LDO3V3
Q1
Si2333DDS
1
3 2
E16
GND
R6
1%
2K
E12
CHRG
R13
1.0
R1
100K
1%
E3
NTC
C6
0.1uF
16V
0402
C1
1uF
6.3V
0402
R5
1%
2.94K
E5
D1
E6
D2
R8
0.00
E15
PROG
JP2
J2
DF3-3P-2DSA
BAT
1
GND
2
EXT. NTC
3
U1
LTC4088EDE
VBUS
11
GND
15
SW 12
NTC
1
DO
13
D1
14
D2
4
PROG
6
C/X
5
CLPROG
2
BAT 9
GATE 8
VOUT 10
LDO3V3 3
CHRG 7
R7
1%
2K
E8 VOUT
E13
CLPROG
L1
3.3uH
LPS4018-332M
C7
10uF
10V
0805
8
dc1007cf
DEMO MANUAL DC1007C
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2016
LT 1116 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application
engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
